Watching a funny movie or television show aids vascular
function, while a stressful or scary movie narrows blood
vessels, according to research presented today at the European
Society of Cardiology’s conference in Paris.

The findings confirm previous studies that suggested a link
between mental stress and the narrowing of blood vessels, said
the lead researcher, Michael Miller of the University of
Maryland School of Medicine in Baltimore. A separate study today
showed that survivors of heart attacks are more likely to
experience a new cardiovascular event if they are angry or
stressed out compared with those who aren’t.

“The take-home message here is laughing is great for your
heart,” Miller said in an interview in Paris.

When volunteers watched parts of a stressful movie, the
opening sequence of “Saving Private Ryan,” their inner blood
vessel lining, known as endothelium, developed a potentially
unhealthy response called vasoconstriction, reducing blood flow,
according to the study. After watching some of a funny movie
such as “There’s Something About Mary,” their blood vessel
lining expanded.

“Everybody we tested to date, with the exception of one
person, had dilation of their blood vessel” after watching bits
of a funny movie, Miller said. The study was conducted on 30
healthy people aged from their 20s to their 50s.

More than 300 measurements were conducted on the arms of
the volunteers, showing a 30 percent to 50 percent difference in
blood vessel diameter between the expansion due to laughter and
the constriction caused by stress, according to the researchers.

‘Great News’

The experiment has since been conducted also on a person
suffering from heart disease, with striking results, he said.

“It suggests that if you are having a really bad day, and
you are having a lot of stress, you can reverse that in a matter
of minutes,” he said. “It’s not only reversing your mood, it’s
reversing your vascular function. That’s great news for the
heart.”

The change in the endothelium caused by laughter appears to
be consistent and similar to the benefits from aerobic exercise
or the use of cholesterol-lowering drugs such as statins, Miller
said. The difference is that laughter has an almost immediate
effect, he said.

Researchers are increasingly focusing on the link between
emotions and cardiovascular disease, the leading cause of death
worldwide. In a third study presented at the conference session
titled “Don’t Worry, Be Happy!,” job strain and long working
hours were associated with higher heart disease and mortality.

Releasing Endorphins

Positive feelings, such as the ones induced by laughter and
listening to relaxing music, are believed to release endorphins
that are recognized by the endothelium, leading to the release
of nitric oxide, according to researchers. Nitric oxide is a
chemical that protects the heart by leading to vessel expansion,
better blood flow, inflammation reduction and the prevention of
cholesterol plaque formation. On the other hand, negative
emotions such as hostility, anger, depression, anxiety and
social isolation have shown to be toxic for the heart.

More research is needed to assess whether laughing on a
regular basis may reduce the risk of heart attacks, Miller said.

Meanwhile, it may help to incorporate laughing on a regular
basis as part of an overall healthy lifestyle, he said.

“Prescription for health should include laughter ” Miller
said. “In other words, eat your veggies, exercise, don’t do
unhealthy things like smoking, and get a good belly laugh every
day.”